Check valve and filter assembly

ABSTRACT

A check valve/filter assembly that is suitable for use in continuous flow fluidic systems. The assembly includes a duckbill type valve member having an annular ring extending radially from the periphery of its entrance end. A hollow cylindrical housing narrows to form an exit nozzle at one of its ends, the other end having an inner diameter proportioned to snugly receive the valve member, the annular ring of the valve member engaging the other end of the housing. A hollow cylindrical sleeve is provided, the sleeve having a relatively large inner diameter at its exit end proportioned to receive the housing, and a relatively small inner diameter at its entrance end, the inner transition surface of the sleeve contacting the annular ring to press it against the housing. In a preferred embodiment of the invention there is provided a filter element that fits on the sleeve.

United States Patent 1191 Goda [451 Apr. 30, 1974 CHECK VALVE AND FILTER ASSEMBLY George Goda, 390 First Ave., New York, NY. 10010 [22] Filed: July 7, 1972 [21] Appl. No.: 269,854

[76] Inventor:

3,572,375 3/1971 Rosenberg l37/525.l X

Primary ExaminerFrank A. Spear v ABSTRACT A check valve/filter assembly that is suitable for use in continuous flow fluidic systems. The assembly includes a duck-bill type valve member having an annular ring extending radially from the periphery of its entrance end. A hollow cylindrical housing narrows to form an exit nozzle atone of its ends, the other end having an inner diameter proportioned to snugly receive the valve member, the annular ring of the valve member engaging the other end of the housing. A hollow cylindrical sleeve is provided, the sleeve having a relatively large inner diameter at its exit end proportioned to receive the housing, and a relatively small inner diameter at its entrance end, the inner transition surface of the sleeve contacting the annular ring to press it against the housing. In a preferred embodiment of the invention there is provided a filter element that fits on the sleeve.

' 1 Claim, 3 Drawing Figures 1 CHECK VALVE AND FILTER ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to valves and, more particularly, to a check valve/filter assembly that is suitable for use in continuous flow fluidic systems. The subject matter of this application is related to subject matter disclosed in my copending U. S. Patent Application Ser. No. 269,856, filed of even date herewith and entitled Check Valve Assembly.

Continuous flow fluidic systems, such as clinical analyzers, are currently in widespread use. In one well known blood analyzing equipment, for example, many samples are simultaneously routed through a complex processing system wherein chemical tests are performed. Various types of chemical reagents are utilized in these tests and it is common practice to provide a relatively large amount of each reagent in a supply container from which the particular reagent is fed to the system by a supply tube. During operation of the system there is a forward pressure in the supply tubes, i.e., the liquid is drawn from the container and flows only in the direction away from the supply container. As each reagent progresses through the system it is typically mixed with other chemicals and/or organic materials being tested. When the system is stopped, such as for maintenance, the forward pressure in the supply tubes is no longer present. If no precautions were taken, traces of mixed chemicals downstream" in the equipment could flow back into the reagent container when operation is temporarily stopped. This is highly undesirable since tests to be performed require nearexact proportions of chemicals and, also, contamination of samples becomes possible. A common technique for preventing this occurrence is to remove the supply tubes from the supply containers before a pause in operation. This method is inefficient and susceptible to human error.

Another problem that arises with respect to reagent supply containers is the presence of precipitates and/or any substance ofa particulate nature which could interfere with tests to be performed in the equipment.

The stated problems could be treated by providing each reagent supply container with a check valve system and a filter system. To be practical, however, these systems must be reliable, easily cleanable and maintainable, and not unduly expensive. l-Ieretofore, there has been no single integrated check valve/filter that meets all of these requirements. It is one object of this invention to provide such an assembly.

SUMMARY OF THE INVENTION The present invention is directed to a check valve/filter assembly and includes a duck-bill type valve member having an annular ring extending radially from the periphery of its entrance end. A hollow cylindrical housing narrows to form an exit nozzle at one of its ends, the other end having an inner diameter proportioned to snugly receive the valve member, the annular ring of the valve member engaging the other end of the housing. A hollow cylindrical sleeve is provided, the sleeve having a relatively large inner diameter at its exit end proportioned to receive the housing, and a relatively small inner diameter at its entrance end, the inner transition surface of the sleeve contacting the annular ring to press it against the housing.

In a preferred embodiment of the invention, the sleeve has an outer annular groove that receives a compressible O-ring which protrudes from the periphery thereof. Further provided is a filter element that includes a mounting ring and a filter disc. The mounting ring is proportioned to receive the entrance end of the sleeve and compress the Oring circumferentially so that the mounting ring is held on the sleeve. The filter disc is supported in the mounting ring in substantially parallel spaced relation to the entrance face of the sleeve. In the preferred embodiment the mounting ring has a radial flange that engages the entrance face of the sleeve and a laterally extending flange which supports the filter disc.

Further features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a preferred embodiment of the invention.

FIG. 2 is an exploded perspective view of the assembly shown in FIG. 1.

FIG. 3 is a side elevational view of the invented assembly functioning within a reagent supply container.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, there is shown a check valve member 21 of the duck-bill type and preferably constructed of a flexible ethylene propylene material. The valve member 21 is tubular at its entrance end and narrows and flattens to form valve lips at its exit end. The entrance end of valve member 21 has an annular ring 22 extending radially from the periphery thereof. The lips allow liquid to flow from the exit end under mild pressure, but are forced more tightly closed by liquid pressure from the exit end.

A hollow cylindrical housing 23, preferably formed of a rigid inert plastic such as polypropylene, narrows to form an exit nozzle 24 at one of its ends. The other end 25 of housing 23 has an inner diameter proportoned to snugly receive the valve member 21, the annular ring 22 engaging the end 25.

A hollow cylindrical sleeve 26, which may be formed of tefion, has a relatively large inner diameter at its exit end 27 that is proportioned to receive the housing 23, and a relatively small diameter at its entrance end 28.

The inner diameter at entrance end 27 is preferably of slightly smaller diameter than the outer diameter of housing 23 so that the housing can be fitted in and retained. The inner transitional surface 29 of the sleeve 26 contacts the annular ring 22 of valve member 21 and presses the ring against the end 25 of the housing.

The sleeve 26 has an outer annular groove 29 that is preferably located closer to the entrance end 28. A flexible O-ring 30 is fitted in the groove 29 and protrudes from the periphery thereof. A filter element'31 includes a mounting ring 32, which may be formed of polypropylene, and a filter disc 33. The mounting ring 32 has an inner diameter that is proportioned to receive the entrance end of the sleeve 26 and compress the O- ring 30 circumferentially. In the illustrated embodiment, the mounting ring has a radial flange 34 that en- 32 also'has a laterally extending flange 35 that is proportioned to receive and hold the filter disc 33, which is typically fonned of sintered polyethylene. The filter disc 33 is supported in substantially parallel spaced relation to the entrance face of the sleeve 26 and is also spaced from the flange 34 to maximize effective filter area.

Referring to FIG. 3, the operation of the invented assembly is illustrated as functioning within a reagent supply container 40 that holds a liquid reagent 41. A

flexible plastic supply tubing 42 is fitted on the exit nozzle 24 of the assembly (FIGS. 1 and 2) which, even with light tubing attached, preferably has sufficient weight to sink near the bottom of container 40 for most reagents 41. In operation, a positive pressure in the tubing 42 draws liquid through filter disc 33 and then through the valve member 21 whose lips are forced open. When the positive pressure is not present, the lips of valve member 21 close and prevent the contaminating backflow of reagent in the tubing 42.

A functioning embodiment of the invention was constructed of the stated preferred materials and was found to operate satisfactorily in various reagents. The inexpensive prototype assembly, which consisted of only six parts, was easily disassembled for cleaning and- /or to change the filter element 33 or the valve member 21.

I claim: 1. A check valve/filter assembly comprising:

a a duck-bill type valve member having an annular ring extending radially from the periphery of its entrance end;

' b a hollow cylindrical housing which narrows to form an exit nozzle at one of its ends, the other end having an inner diameter proportioned to snugly receive the valve member, the annular ring of said valve member engaging said other end of said housing;

c a hollow cylindrical sleeve having a relatively large inner diameter at its exit end proportioned to receive said housing and a relatively small inner diameter at its entrance end, the inner transition surface of said sleeve contacting said annular ring to press it against said housing, said sleeve having an outer annular groove;

d a compressible O-ring fitted in said annular groove and protruding from the periphery thereof;

e a filter element including a mounting ring and a filter disc, said mounting ring being proportoned at one end to receive the entrance end of said sleeve and compress said O-ring circumferentially such that it is removably mounted on said sleeve, the

other end of said mounting ring having a laterally extending flange proportioned to removably re- 

1. A check valve/filter assembly comprising: a a duck-bill type valve member having an annular ring extending radially from the periphery of its entrance end; b a hollow cylindrical housing which narrows to form an exit nozzle at one of its ends, the other end having an inner diameter proportioned to snugly receive the valve member, the annular ring of said valve member engaging said other end of said housing; c a hollow cylindrical sleeve having a relatively large inner diameter at its exit end proportioned to receive said housing and a relatively small inner diameter at its entrance end, the inner transition surface of said sleeve contacting said annular ring to press it against said housing, said sleeve having an outer annular groove; d a compressible O-ring fitted in said annular groove and protruding from the periphery thereof; e a filter element including a mounting ring and a filter disc, said mounting ring being proportoned at one end to receive the entrance end of said sleeve and compress said O-ring circumferentially such that it is removably mounted on said sleeve, the other end of said mounting ring having a laterally extending flange proportioned to removably receive said filter disc. 